1. Field of the Invention
This invention relates to a cooling apparatus boiling and condensing refrigerant which cools a heat-generating member by heat transfer with boiling of a refrigerant.
2. Description of the Related Art
A conventional cooling apparatus boiling and condensing refrigerant is indicated in FIG. 7, by way of example.
This cooling apparatus boiling and condensing refrigerant is comprised of a refrigerant container 100 which reserves refrigerant liquid, a pair of headers 110, 120 each of which is connected to the refrigerant container 100, a plurality of tubes 130 provided between the header 110 and the header 120, and heat radiating fins 140 for radiating heat transferred from the tubes 130 into the air. A heat-generating element 150 is attached to a bottom surface of the refrigerant container 100.
A separating wall 160 which determines a direction of circulation of the refrigerant is provided in the refrigerant container 100. Accordingly, as indicated by arrows in the drawing, the refrigerant, in the refrigerant container 100, boiled by receiving heat from the heat-generating element 150 is introduced, from the refrigerant container 100 to the header 110, from the header 110 to the other header 120, being cooled upon passing through each tube 130, and is circulated into the refrigerant container 100 from the header 120, as a condensed refrigerant.
The above cooling apparatus boiling and condensing refrigerant generates refrigerant vapor mostly at a portion to which the heat-generating element 150 is attached, however, the refrigerant vapor can be generated at other portions. Accordingly, in the refrigerant container 100 on which the heat-generating element 150 is mounted, the heat is transferred, in progression, from the portion to which the heat-generating element 150 is attached. The temperature of the refrigerant container 100 is increased at a portion which is near the circulating portion to which the header 120 is connected. Accordingly, the refrigerant vapor is also generated near the circulating portion of the refrigerant container 100. Therefore, when the refrigerant vapor enters the header 120, it can oppose the condensed refrigerant which is circulated from the header 120 into the refrigerant container 100. Due to this, a malfunction of refrigerant circulation is caused and the efficiency of the apparatus is degraded.
In view of the drawbacks mentioned above, according to the invention, there is provided a cooling apparatus boiling and condensing refrigerant in which a malfunction of refrigerant circulation, caused by opposed flows between condensed refrigerant and refrigerant vapor, can be prevented and the degradation of the efficiency thereof can be eliminated. The other purpose of the invention is to provide the cooling apparatus boiling and condensing refrigerant in which the circulation of the refrigerant can be performed smoothly without increasing the size thereof and can be more easily assembled.
The first Aspect of the Invention
According to the invention, there is provided a cooling apparatus boiling and condensing refrigerant in which refrigerant reserved in a refrigerant container can be boiled and evaporated by receiving heat from a heat-generating member and can be used to cool the heat-generating member by radiating latent heat of refrigerant vapor from a heat radiating portion; and when it is assumed that a portion of the upper surface of the refrigerant container on which a mounting portion of the heat-generating member is projected is referred to a boiling area, the tube located within the boiling area has a passage defined by a lower end opening portion connected to the refrigerant container and has a passage cross sectional area larger than that of the tubes located outside the boiling area.
According to the constitution, the refrigerant vapor evaporated by receiving the heat from the heat-generating member can be introduced, with the high priority, in the tube located within the boiling area. Thus, the refrigerant vapor is introduced into a header tank through the tube located within the boiling area, and the refrigerant vapor diffused in the header tank is circulated into the refrigerant container in the form of a condensate after being cooled while passing the tubes located out of the boiling area.
In the present invention, the circulation of the refrigerant can be improved by making the size of a passage cross section of the lower end opening portion of the tube located within the boiling area larger than other tubes. Therefore, neither the size of the heat radiating portion nor the overall size of the apparatus are increased.
The length of the tube located within the boiling area can be identical to that of the tube located out of the boiling area. Both end portions of each tube can be secured in the vertical direction. Thus, the apparatus of the invention can be more easily assembled and can be mass-produced at a lower cost than the cooling apparatus boiling and condensing refrigerant described in the prior art.
The Second Aspect of the Invention
In the cooling apparatus boiling and condensing refrigerant according to the first aspect of the invention, the tube located within the boiling area has a shape in which the lower end portion thereof is suddenly increased in its passage cross section towards the lower end opening portion. Thus, the refrigerant vapor can be effectively introduced to the tube located in the boiling area.
The Third Aspect of the Invention
In the cooling apparatus boiling and condensing refrigerant according to the first aspect of the invention, the tube located within the boiling area has a passage cross section larger than that of the tube located outside the boiling area, over the entirely of the length from the lower end opening portion to be connected to the refrigerant container, to an upper end opening portion to be connected to the header tank.
The Fourth Aspect of the Invention
According to the invention, there is provided a cooling apparatus boiling and condensing refrigerant in which refrigerant reserved in a refrigerant container can be boiled and evaporated by receiving heat from a heat-generating member and can be used to cool the heat-generating member by radiating latent heat of refrigerant vapor from a heat radiating portion; and when it is assumed that a portion of the upper surface of the refrigerant container on which a mounting portion of the heat-generating member is projected is referred to a boiling area, the plurality of tubes are comprised of a first tube group located within the boiling area and a second tube group located out of the boiling area and the adjacent tubes of the first tube group are spaced at a distance smaller than a distance of adjacent tubes of the second tube group.
According to the constitution, the refrigerant vapor evaporated by receiving the heat from the heat-generating member can be introduced, with the high priority, in the tube located within the boiling area, and the adjacent tubes of the first tube group are spaced at a distance smaller than a distance of adjacent tubes of the second tube group. Thus, the refrigerant vapor can be collectively introduced into the tubes of the first tube group.
In the present invention, the circulation of the refrigerant can be improved by merely making the distance between adjacent tubes of the first tube group located within the boiling area smaller than that of the second tube group located out of the boiling area. Therefore, neither the size of the heat radiating portion nor the overall size of the apparatus are increased.
The length of the tubes located within the boiling area can be identical to that of the tube located out of the boiling area. Both end portions of the tube can be secured in the vertical direction. Thus, the apparatus of the invention can be more easily assembled and can be mass-produced at a lower cost than the cooling apparatus boiling and condensing refrigerant described in the prior art.
The Fifth Aspect of the Invention
In the cooling apparatus boiling and condensing refrigerant according to any one of the aspects 1 through 4, the refrigerant container is comprised of a plurality of intermediate plates having opening portions extending through the thickness thereof, a heat receiving plate which is provided on its surface with the heat-generating member, and a heat radiating plate which is provided on its surface with the tubes; the plural intermediate plates are multilayered between the heat receiving plate and the heat radiating plate; the opening portions of the intermediate plate adjacent to the heat radiating plate are made large corresponding to the boiling area projected on the heat radiating plate.
According to the constitution, the refrigerant vapor boiled and evaporated by receiving the heat from the heat-generating member is introduced in the tubes located within the boiling area through the opening portions of the intermediate plate adjacent to the heat radiating plate. As the opening portions of the intermediate plate can be increased according to the boiling area, the performance of the apparatus can be improved due to smooth circulation of the refrigerant and easy passage of the refrigerant vapor.
The present invention may be more fully understood from the description of the preferred embodiments of the invention set forth below, together with the accompanying drawings.